Proper airway establishment and management currently is problematic in all realms of the medical sphere, especially as concerns lesser-trained personnel. The plight of the Emergency Medical Technician (EMT) richly illustrates this point. In an emergency medical event, airway management is the most important factor in determining the survival and subsequent outcome of the patient. The majority of patients who are semiconscious or unconscious due to trauma, seizures, heart-attacks, drugs, alcohol, or a host of other causes will require this airway establishment and management to some degree. Under these conditions, muscles in the patients relax. When muscles in the mouth and throat begin to relax, the tongue tends to slide backward against the back of the throat causing an airway obstruction. When this occurs, the first step is to open the patient's airway through the use of manual positional adjustments. This includes chin lift, hyperextension of the head, and jaw thrust. If these maneuvers are unsuccessful or contraindicated, then the airway must be established by mechanical means (i.e., oropharyngeal airway, nasopharyngeal airway, laryngeal mask airway, or endotracheal tube).
The oropharyngeal airway (OPA) can be inserted into the mouth to establish an open passage to allow for airflow into the lungs. Since this device passes down the centerline of the tongue, it is centered on the largest of the gag reflexes at the uvula. As long as the patient does not regain consciousness and begin to vomit or gag (thereby obstructing the airway once again) things will be okay. However, acceptance of this device by the conscious patient is poor, and the possibility of dental damage is real.
The nasopharyngeal airway (NPA) is a device that is inserted into the nasal cavity until it reaches the upper pharyngeal region of the throat, just below the base of the tongue. It allows for oxygen flow past the obstruction produced by the tongue. Because the NPA is a somewhat intrusive procedure to delicate nasal tissues, it can cause nose bleed, hemorrhage or ulceration. If improperly inserted, it can inadvertently be routed into the patient's brain. It cannot be used in patients with such conditions as impaired blood-clotting, deviated septum, sinusitis, heavy nasal congestion, enlarged adenoids, and nasal trauma. When properly inserted, the NPA can stimulate the gag reflex and induce vomiting. Acceptance of this device by the conscious patient is poor.
The very high skill level required to place the laryngeal mask airway (LMA) and the endotracheal tube (ETT) is beyond the scope of most healthcare providers. In order to insert an ETT or LMA, the patient must totally unconscious. If this is not the case, the patient will have to be heavily sedated. Few healthcare providers are allowed to administer sedation drugs to a patient independently. The only options, at this point, is to wait until the patient deteriorates into total unconsciousness in order to insert the ETT or LMA, or await the arrival of higher skilled providers.
Once the patient's airway is established, respiratory status is evaluated to determine what level of management is required. Judgment of this by EMTs is highly subjective. “Is the patient breathing adequately?” is the criteria by which this judgement call is made. If the respiratory status appears normal, intervention may only involve administration of supplemental oxygen, possibly by use of the Nasal Cannula (NC). The NC is an oxygen tube with two prongs which insert into the immediate openings of the patient's nostrils. Some NCs even have provisions for CO2 monitoring. They cannot, though, be used effectively in patients with certain conditions, including nasal trauma, sinusitis, enlarged adenoids, apnea and colds. Barring the restrictions of its use, the NC can provide a passive supply of oxygen and valuable monitoring of expired gases if the patient chooses to breathe through his or her nose. Sometimes that is not the case.
If the patient exhibits signs of impaired respiratory effort, the go-to device most commonly employed by healthcare professionals to provide positive airway pressure is the bag-valve mask (BVM). This device consists of a large, one-size-fits-all mask with a bag attached to it which, when squeezed with both hands, allows air to be forced into the lungs of the patient. In many cases, it takes two persons to operate this device—one to hold the mask down onto the patient's face and force the patient's jaw into the mask to form a complete seal, and the other to squeeze the bag. Other needed medical interventions to the patient cannot be addressed until the airway has been secured. Fully sealing the mask against the patient's face is key in this procedure, and it does take a fair amount of skill and practice to be able to do so. Certain factors, such as advanced age, obesity, absence of teeth, anatomical variations of the jaw or throat structure, cervical spine injury, and/or facial hair may add to the complexity of using a BVM, or even render it impossible to use. An agitated or claustrophobic patient fighting mask placement adds to the problems already listed. Even with proper usage, the mask can cause additional trauma to eyes (corneal abrasions). Excessive positive airway pressure from the BVM can result in damage to lung tissues, inflation of the stomach, vomiting, aspiration, and subsequent airway obstruction. Certain BVMs will allow for the monitoring of the patient's expired CO2 gases. If the BVM can somehow be properly sealed and used in the first place, this valuable monitoring information can be used to improve the outcome of the patient.
Airway establishment and management problems do extend to other realms of the medical sphere, as well. The need for airway establishment and management may crop up any time in patients who are receiving sedation and/or pain management. These medications are routinely administered to patients as they undergo certain procedures in departments, such as Emergency Rooms, Catheterization Labs, Gastrointestinal Labs, Radiology Labs, etc. As mentioned before, any agent that induces relaxation of the muscles in the mouth can cause obstruction of the airway. Certain risk factors in the patient, including sensitivity and overreaction to sedatives or pain medication, obesity, infirmity, abnormal airway and obstructive sleep apnea increase the likelihood that airway obstructions will occur. When complications do arise, the procedure is halted until the complication has been resolved. In the case of procedures involving the use of the oral cavity as an entry point (such as GI Endoscopy) the procedure must sometimes be halted, and the tubes removed in order to address the problem. Typical resolution of these airway problems may involve the use of a mask (the problems of which have been previously discussed) to provide oxygen, along with an NPA to open the airway (the problems of which have also been previously discussed). If these attempts are unsuccessful, a person skilled in airway management must be summoned from another department to address the problem. Typically, the solution will involve the insertion of an ETT or LMA. Heavy sedation is required to paralyze the patient prior to this intubation. This is not always desirable in a routine procedure.
Persons administering anesthesia gases in the operating room often experience the same problems as those persons in other departments of the medical sphere. Current wisdom states that the depth and duration of anesthesia should be minimized as much as possible, especially for the very young and the elderly, in order to minimize the risks and complications therein. Oftentimes, though, the level of anesthesia is determined, not by the medical procedure being performed, but by the type of airway device that is being used. The use of ETTs and LMAs, and even traditional oropharyngeal airways requires deep sedation or paralysis of the patient. NPA type devices, with their previously discussed shortcomings, are an option, but they must be used in conjunction with a mask (the problems of which have been previously discussed, also).
Airway establishment and management problems may arise in the post-operative setting. The patient must be heavily sedated up to the time when ETTs or LMAs are removed. In the transitional period after removal of these devices, when the patient is being “weaned” off of anesthetic gases, it is determined whether the patient will be able breath on his or her own. Monitoring of oxygen saturation is routinely performed during this weaning period. There is, though, no 100% reliable way to monitor ETCO2. Upon removal of the breathing tubes, if autonomous breathing does not occur, the BVM (with its attendant problems) must be deployed. The NPA (with its attendant problems) may also be deployed to keep the airway open. If the patient is too weak, and these strategies fail, the patient must be heavily sedated, and once again, the ETT or LMA must be re-inserted.
If the patient is successful in attaining autonomous breathing in the post-operative setting, pain medications are commonly administered. Because pain medications relax the tongue and throat muscles, in many circumstances, the patient's need for pain relieving drugs must be balanced against the need to keep the patient's airway open. Oftentimes, this results in the patient receiving much less pain relief than is needed.
Airway establishment and management problems, as mentioned above, extend to doctor's offices, clinics, outpatient spine treatment centers—they even extend to industrial and home emergency management. At most, the industrial or home first aid kit will include a mask and an oxygen bottle. At second best, it will contain a traditional oropharyngeal airway device. At worst, it will contain nothing, relying on EMTs to restore the airway. And, thus, we return to the beginning.